Device and method for skinning fish fillets

ABSTRACT

An apparatus for skinning fish fillets includes a skinning knife to separate skin from the fish fillets, a delivery element to deliver the fish fillets into the region of the skinning knife, a driver roller for the skin separated from the fish fillets, a contact pressure element including a device to indicate a position of the contact pressure element, a discharge element to carry away the skinned fish fillets; and an element arranged in a region of the driver roller to monitor an input of fish fillets onto the driver roller and an output of fish fillets from the driver roller.

This application is a National Stage Application of PCT/EP2008/006692, filed Aug. 6, 2008, which designates the United States and claims the priority of German patent application DE 10 2007 041 167.9, filed on Aug. 24, 2007, the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention concerns an apparatus for turning fish fillets, comprising a delivery element for delivery of the fish fillets into the region of a turning station, the turning station itself, and a discharge element for discharging the turned fish fillets, wherein the turning station is constructed and designed for turning the fish fillets about the longitudinal axis and an axis running perpendicularly to the longitudinal axis.

Apparatuses of this kind are used in the food industry and in particular in the fish-processing industry. The apparatuses turn the products about one or two axes in order to position and align the products optimally for the subsequent processing steps. The reasons for turning may be manifold. Thus products can be turned accordingly about their longitudinal axis in order to remove unwanted product areas which, before turning, point in the direction facing away from the delivery belt, downwardly in the subsequent step, that is, from the side facing towards the delivery element, or vice versa. The desired direction of travel, that is, the side with which the product leads, can vary for reasons of the product geometry, the accessibility to processing tools or for other reasons, so that the product accordingly must be turned about an axis which runs perpendicularly to the longitudinal axis. To sum up, it can be stated that different positions must be attained, that is, e.g. skin down or flesh down on the one hand and headfirst or tail first on the other hand, by turning about one or more axes. The “headfirst or tail first” direction on the one hand and the “up or down” position on the other hand can be in any order, however.

By the example of fish filleting, the preferred field of application of the above apparatus becomes clear. Depending on preliminary positioning, the fish is oriented e.g. tail first. During filleting of the fish, the two fish fillets separated from the backbone usually fall onto the flesh side which is opposite the skin. For subsequent trimming, skin removal or the like, however, it is necessary with some processes for the skin side to be down and the fish fillets to be conveyed headfirst. But turning may also be necessary with other products, such as e.g. chicken fillets or the like, that is, in particular soft products, in order e.g. to bring a fat side from being up to down or a narrow product area from the leading position to a trailing position.

In practice, with reference to the above example with the fish fillets an auxiliary means is used, so that after separation from the backbone the fish fillets drop directly onto the skin side, so that only turning about the axis perpendicular to the longitudinal axis is still necessary in order to change the fish fillets from their tail first direction to headfirst. But these auxiliary means are unreliable, so that frequently there are faults, as a result of which the turning process is disturbed. Up to now, usually turning devices or apparatuses which are constructed and designed for turning the products about a single axis, that is, either about the longitudinal axis or about the axis perpendicular to the longitudinal axis, have been used. For turning about the longitudinal axis, for example DE 40 22 461 C1 is mentioned here. However, a disadvantage with apparatuses of this kind is that for each turning operation, that is, turning about the longitudinal axis on the one hand and turning about the axis perpendicular to the longitudinal axis on the other hand, separate turning elements are provided. This increases the complexity of the apparatuses. Secondly, increased spatial requirements are necessary. Furthermore, with the apparatuses described above rinse water or the like is usually used to assist the turning operation. As a result, firstly there is an increase in water consumption. Secondly, the risk of contamination of the products to be turned increases due to the rinsing operation.

Therefore apparatuses were developed which are constructed and designed to alter both position changes, namely a change from skin side down to up or vice versa and a change of direction of travel from tail first to headfirst or vice versa, in a single superimposed turning operation. By means of such an apparatus the products can therefore be turned on the one hand about the longitudinal axis so that the fish fillets, which are flesh side down on the delivery element, lie with the skin side on the discharge element after turning. On the other hand the fish fillets which are conveyed tail first on the delivery element are turned about an axis which runs perpendicularly to the longitudinal axis, so that the fish fillets are conveyed headfirst on the discharge element. Apparatuses of this kind for turning about two axes simultaneously have a conveyor belt of which the length approximately corresponds to the length of the longest product to be processed. Above said conveyor belt is a further conveyor belt which corresponds to the lower conveyor belt and with the latter forms a transport unit. This transport unit is pivotable about an axis transverse to the direction of transport. If a product is located for example with the flesh side on the lower conveyor belt, the transport unit is turned through 180°, so that the product falls onto the conveyor belt which was initially on top and is now underneath, namely skin side down. At the same time the rotation through 180° causes the direction of travel to change from tail first to headfirst. This known solution is very complex with a large number of moving parts and firstly requires a very large amount of space. Secondly, the positioning of the products on the discharge element is not optimal.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to propose a compact turning station by means of which the products can quickly and reliably be turned about two axes.

This object is achieved by an apparatus having the features mentioned hereinbefore by the fact that the turning station comprises a turning drum which is arranged between the delivery element and the discharge element in the direction of transport T of the fish fillets, the discharge plane E_(A) defined by the discharge element being located below the delivery plane E_(Z) defined by the delivery element, the turning drum being assigned a vacuum unit and the shell of the turning drum being perforated for applying a vacuum to the fish fillets. By means of the turning drum a superimposed turning movement can be carried out, so that with a single turning element both turning about the longitudinal axis and turning about the axis perpendicular to the longitudinal axis can be carried out. Due to the arrangement from delivery element to discharge element, this double turning movement is assisted. The arrangement of the turning drum “between” delivery element and discharge element in this context means that the fish fillets after leaving the delivery element initially reach the turning station and from there are passed on to the discharge element. A further advantage lies in that, due to the vacuum, controlled holding and release of the products on the turning drum or from the turning drum respectively is guaranteed. In other words, in particular the moment of release of the products from the turning drum to the discharge element can be determined, ensuring optimum positioning of the products of the discharge element. Perforation means any kind of apertures, e.g. bores, slots or the like, which allow the products to be drawn by suction to the shell of the turning drum.

An appropriate development provides that the turning drum extends across the full width of the delivery element and/or discharge element. This ensures that the fish fillets are turned on the delivery element or discharged on the discharge element independently of their position.

A preferred embodiment is characterised in that the discharge element, which is also constructed as a belt conveyor, is arranged below the turning drum. As a result, the fish fillets falling off the turning drum “land” on the discharge element reliably.

Advantageously, between the turning drum and the discharge element is arranged at least one roller which is at a distance from both the turning drum and the discharge element. As a result of the roller a braking action is obtainable, leading to stretching of the fish fillet on the discharge element. In other words the fish fillets which, falling off the turning drum, land with one area on the roller are temporarily retained so that the movement of the discharge element leads to the mentioned stretching until the fish fillet is completely released from the turning drum.

A preferred embodiment of the invention is distinguished in that between the delivery element and the turning drum is arranged a roller element as a guide element. Hence the gap between the delivery element and the turning drum, of which the circumferential surface is round, can be effectively and easily closed so that the fish fillets can be transferred reliably.

Preferably, in the region of the roller a roller element is arranged as a stripper element. To put it another way, the roller is arranged and designed in such a way that the fish fillets are guided approximately 270° round the turning drum. This means that the roller, starting from the vertical centre axis A, is arranged with an offset of more than 180° and less than 270°. This stripper element ensures that the fish fillets are reliably released from the turning drum and drop via the roller onto the discharge element.

BRIEF DESCRIPTION OF THE DRAWINGS

Further appropriate or advantageous features and embodiments are apparent from the subsidiary claims and the description. A particularly preferred embodiment is described in more detail with the aid of the attached drawing. The drawing shows:

FIG. 1 a schematic view of a turning station according to the invention.

BRIEF DESCRIPTION OF THE EMBODIMENTS

The shown turning station or the apparatus is used to turn fish fillets in plants for the processing of fish. Naturally, the turning station can also be operated as an individual unit, this being for other products as well.

The apparatus 10 shown in FIG. 1 schematically and only as a detail comprises a delivery element 11 for delivering fish fillets (hereinafter also referred to as the product) 12 into the region of a turning station 13, the turning station 13, and a discharge element 14 for discharging the turned products 12. The delivery element 11 and the discharge element 14 are designed as belt conveyors in the shown embodiment, the conveyor belt 15 or 16 being guided about guide and/or drive rollers 17 or 18. Both the delivery element 11 and the discharge element 14 can be designed in another known manner, for example as a chute or the like. The turning station 13 is arranged in such a way between the delivery element 11 and the discharge element 14 that the products 12 can be transferred reliably. The turning station 13, as it were, makes the connection between the delivery element 11 and the discharge element 14. In the shown embodiment the delivery element 11 and the discharge element 14 are arranged in alignment one behind the other in a top view. An angular arrangement of delivery element 11 and/or discharge element 14 is possible as well. Also, the delivery element 11 and/or the discharge element 14 can be arranged at an angle unlike the example in FIG. 1, in which they run mainly horizontally.

The turning station 13 is constructed and designed for turning the products 12 about its longitudinal axis and about an axis perpendicular to the longitudinal axis. To put it another way, the turning station 13 is constructed and designed for changing the positions of the products 12 both in relation to the longitudinal axis and about the axis perpendicular to the longitudinal axis. The turning station 13 comprises a turning drum 19 which is mounted at least on one side, but preferably on both sides on a frame 20, housing or the like. The turning drum 19, which is preferably constructed in one part and which can optionally be composed of several individual drums or otherwise, is arranged behind the delivery element 11 in the direction of transport T, as an extension of the delivery element 11 so to speak, but vertically offset from each other. The discharge element 14 is arranged behind the turning drum 19 with reference to the flow of products. This means that the products 12 are initially delivered to the turning station 13 after the delivery element 11, in order then to be forwarded to the discharge element 14. The discharge element 14 is further offset downwardly in relation to the turning drum 19. To put it another way, the plane E_(A) defined by the discharge element 14 is lower than the plane E_(Z) defined by the delivery element 11.

The turning drum 19 is arranged or oriented transversely to the direction of transport T and extends preferably across the whole width of the delivery element 11 and/or the discharge element 14. The centre axis of the turning drum 19 accordingly runs parallel to the centre axes of the guide rollers 17, 18 and therefore transversely to the direction of transport T of the products 12. In other embodiments, the turning drum 19 may also extend only partially across the width of the delivery element 11 or discharge element 14. The turning drum 19 is designed to be movable in rotation. Rotation takes place about the centre axis of the turning drum 19, which runs transversely to the longitudinal axis of the products 12. Relative to the delivery element 11 or to the discharge element 14, the turning drum 19 is stationary. Rotation of the turning drum 19 can be generated e.g. by the products 12 themselves. Preferably, however, the turning drum 19 is actively driven in rotation by means of a drive, not shown, this being in the direction of conveying F (see arrow in FIG. 1). This means that the turning drum 19 is driven in the same direction as the delivery element 11.

The turning drum 19 is optionally assigned a vacuum unit (not shown). In order to be able to transmit the vacuum generated by the vacuum unit, that is, the suction force, to the products 12, the shell 21 of the turning drum 19 is perforated. For this purpose the shell 21 can have openings, bores, slots or other recesses of different shape, number, arrangement and the like. The perforation may be distributed evenly or unevenly over the shell 21 and preferably extends across the whole width of the turning drum 19. The vacuum unit is connected to a control means in order to be able to control applying and switching off the vacuum selectively. But alternatively the turning drum 19 can be provided with a closed shell 21, so that the products 12 stick to the turning drum 19 merely because of their “adhesion capacity” caused by the moisture.

The discharge element 14 is, as already mentioned, arranged below the turning drum 19. “Below” in this context means that the products 12 falling off the turning drum 19 fall onto the discharge element 14. For this purpose one end of the discharge element 14 reaches so far below the turning station 13 that the centres M of the guide or drive roller 18 of the discharge element 14 on the one hand and of the turning drum 19 on the other hand lie one above the other approximately vertically on a common axis A. The position of the discharge element 14 may, however, in particular also vary in relation to the horizontal position, in such a way that the discharge element 14 is displaced in the direction of transport T or in the direction opposite the direction of transport T.

Between the turning drum 19 and the discharge element 14 is arranged at least one roller 22. The roller 22 is at a distance from both the turning drum 19 and the discharge element 14. The roller 22 is preferably attached to the frame 20. There are, however, other options and positions for attachment as well. The roller 22 can also be replaced by another element which is particularly suitable for retaining the products 12 falling off the turning drum 19. The roller 22 is oriented with its centre axis transversely to the direction of transport T, so that the roller runs parallel to the turning drum 19 and to the guide or drive roller 18. Preferably, the centre of the roller 22 also lies on the vertical axis A which runs through the centres M of the turning drum 19 and of the guide or drive roller 18. Naturally the roller 22 can also be offset horizontally and/or vertically. Preferably the roller 22 is arranged stationarily on the frame 20. Independently of the arrangement on the frame 20, the roller 22 can also be fixed or movable. Usually the roller 22 is movable in rotation about its centre axis. In other embodiments the roller 22 can also be driven.

The turning drum 19, which has a much larger diameter than the roller 22, lies with its maximum diameter approximately in the plane E_(Z) defined by the delivery element 11. As a result, transfer of the products 12 from the delivery element 11 onto the turning drum 19 is made easier. However, the turning drum 19 can also take up other positions relative to the delivery element 11, in particular be offset downwardly as well.

Furthermore, the turning drum 19 in the region of the shell 21 is assigned at least one roller element 23. Preferably, however, the turning drum 19 is assigned two roller elements 23, 24. The roller elements 23, 24 are, however, not limited to a cylindrical shape, but can have other geometrical shapes. The roller elements 23, 24 can also be replaced by rod-shaped, strip-shaped or other shaped elements. Assignment of the roller elements 23, 24 to the shell 21 means that the roller elements 23, 24 are located close to the shell 21 or even in contact with it. Also, an operative connection between the roller elements 23, 24 and the turning drum 19 is possible.

One of the roller elements 23 is designed and arranged as a guide element. For this purpose the roller element 23 is located in a wedge-shaped region formed between the delivery element 11 and the turning drum 19. By means of the roller element 23, the products 12 transported from the delivery element 11 are prevented from slipping into the wedge-shaped region. In other words, the roller element 23 ensures reliable transfer of the products 12 from the delivery element 11 onto the turning drum 19.

The other roller element 24 is arranged in the region of the roller 22 and designed as a stripper element. Preferably the roller element 24 fits closely against the turning drum 19 in order to ensure stripping of the products 12 from the turning drum 19. In relation to the direction of conveying F the products 12 on the turning drum 19, the roller element 24 is located behind the roller 22. This ensures that the products 12 stripped by the roller element 24 drop onto the roller 22. Naturally the roller element 24 can take up other positions as well. In the direction of conveying of the turning drum 19, the roller element 24 is, starting from the centre axis A, arranged with an offset of more than 180° and less than 270°. Naturally the position of the roller element 24 in relation to the centre axis A can also vary.

Below, the principle of the method is described in more detail purely by way of example with reference to turning fish fillets which lie on the flesh side and are conveyed tail first. The fish fillets (products 12) travel in the direction of the turning station 13 on the delivery element 11, tail first and lying with their flesh side on the delivery element 11. In the region of the roller element 23 the products 12 are transferred to the turning drum 19 which turns in the same direction (direction of conveying F) as the delivery element 11 (direction of transport T). Due to the partial pressure generated in the turning drum 19, the rotating product 12 and in particular the tail side clings to the shell 21 of the turning drum 19. In the direction of conveying F, the nape piece, which is thicker and heavier than the tail side, is behind. Due to the greater mass and greater weight, the nape piece folds round in the course of deflection/rotation. The tail end is drawn by suction until it is stripped off by the roller element 24 and/or released from the turning drum 19 by loss of vacuum or controlled switching off of the vacuum. In the shown apparatus 10, the product 12 then drops onto the roller 22 located below the turning drum 19. While the nape piece, which is now in front, is already located on the discharge element 14, the tail end can still be located on the roller 22. Due to the braking action, stretching of the product 12 results. But the product 12 can also drop directly from the turning drum 19 onto the discharge element 14. On the discharge element 14 the product 12 then lies on the one hand headfirst and on the other hand on the skin side. 

1. An apparatus for skinning fish fillets, comprising: a skinning knife to separate skin from the fish fillets, a delivery element to deliver the fish fillets into the region of the skinning knife; a driver roller for the skin separated from the fish fillets; a contact pressure element arranged to be deflected by a skinned fish fillet and including a device to indicate a position of the contact pressure element; a discharge element to carry away the skinned fish fillets; and an element arranged in a region of the driver roller to monitor an input of fish fillets onto the driver roller and an output of fish fillets from the driver roller.
 2. The apparatus according to claim 1, wherein the element to monitor the fish fillets in the region of the driver roller is arranged in front of the contact pressure element in a direction of transport of the fish fillets.
 3. The apparatus according to claim 1, wherein the monitoring element comprises a light barrier.
 4. The apparatus according to claim 3, wherein the light barrier is operatively arranged so that a full width of the driver roller transverse to the direction of transport is monitored.
 5. The apparatus according to claim 3, wherein the roller has a rotational axis and the light barrier is parallel to the rotational axis of the driver roller.
 6. A method for skinning fish fillets, comprising: delivering a product stream composed of fish fillets on a delivery element, skinning the fish fillets with a skinning knife, deflecting a contact pressure element by the fish fillets during the skinning of the fish fillets; triggering a signal corresponding to a deflection of the contact pressure element; separately carrying away skinned fish fillets on a discharge element (17) on the one hand and separated skin into a gap formed between a driver roller and the skinning knife on the other hand; and monitoring an input of the fish fillets onto the driver roller and an output of the fish fillets from the driver roller.
 7. The method according to claim 6, wherein the monitoring includes interrupting a light barrier upon passage of each fish fillet from the delivery element onto the driver roller, a and releasing the interruption when the fish fillet leaves the driver roller.
 8. The method according to claim 6, wherein the monitoring includes monitoring the driver roller across a full width of the driver roller.
 9. The method according to claim 6, and further including correlating with each other the signal triggered by deflection of the contact pressure element and information obtained from the monitoring step to control and/or regulate measures for eliminating faults in a flow of the fish fillets. 